RESUMO
Chorioamnionitis, inflammation of fetal membranes, is an important cause of preterm birth and a risk factor for the development of adverse neonatal outcomes including sepsis and intestinal pathologies. Intestinal bile acids (BAs) accumulation and hepatic cytokine production are involved in adverse intestinal outcomes. These findings triggered us to study the liver and enterohepatic circulation (EHC) following intra-amniotic (IA) lipopolysaccharide (LPS) exposure. An ovine chorioamnionitis model was used in which circulatory cytokines and outcomes of the liver and EHC of preterm lambs were longitudinally assessed following IA administration of 10 mg LPS at 5, 12 or 24h or 2, 4, 8 or 15d before preterm birth. Hepatic inflammation was observed, characterized by increased hepatic cytokine mRNA levels (5h - 2d post IA LPS exposure) and increased erythropoietic clusters (at 8 and 15 days post IA LPS exposure). Besides, 12h after IA LPS exposure, plasma BA levels were increased, whereas gene expression levels of several hepatic BA transporters were decreased. Initial EHC alterations normalized over time. Concluding, IA LPS exposure induces significant time-dependent changes in the fetal liver and EHC. These chorioamnionitis induced changes have potential postnatal consequences and the duration of IA LPS exposure might be essential herein.
Assuntos
Corioamnionite/imunologia , Circulação Êntero-Hepática/imunologia , Feto/irrigação sanguínea , Hepatite/imunologia , Nascimento Prematuro/imunologia , Animais , Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Corioamnionite/sangue , Corioamnionite/patologia , Citocinas/sangue , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Feto/imunologia , Regulação da Expressão Gênica/imunologia , Hepatite/sangue , Hepatite/patologia , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/imunologia , Fígado/imunologia , Fígado/patologia , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Gravidez , Nascimento Prematuro/sangue , Carneiro Doméstico , Fatores de TempoRESUMO
Chorioamnionitis can lead to inflammation and injury of the liver and gut, thereby predisposing patients to adverse outcomes such as necrotizing enterocolitis (NEC). In addition, intestinal bile acids (BAs) accumulation is causally linked to NEC development. Plant sterols are a promising intervention to prevent NEC development, considering their anti-inflammatory properties in the liver. Therefore, we investigated whether an intra-amniotic (IA) Ureaplasma parvum (UP) infection affected the liver and enterohepatic circulation (EHC) and evaluated whether an IA administered plant sterol mixture dissolved in ß-cyclodextrin exerted prophylactic effects. An ovine chorioamnionitis model was used in which liver inflammation and the EHC were assessed following IA UP exposure in the presence or absence of IA prophylactic plant sterols (a mixture of ß-sitosterol and campesterol dissolved in ß-cyclodextrin (carrier)) or carrier alone. IA UP exposure caused an inflammatory reaction in the liver, histologically seen as clustered and conflated hepatic erythropoiesis in the parenchyma, which was partially prevented by IA administration of sterol + ß-cyclodextrin, or ß-cyclodextrin alone. In addition, IA administration of ß-cyclodextrin prior to UP caused changes in the expression of several hepatic BAs transporters, without causing alterations in other aspects of the EHC. Thereby, the addition of plant sterols to the carrier ß-cyclodextrin did not have additional effects.